FAS and carcinoma of esophagus: Logistic regression analysis indicated that there was no significant association between esophageal carcinoma and gene polymorphisms of Fas‐670A/G, Fas‐1377G/A and FasL‐844 T/C (Fas‐670AG, P = 0.820; Fas‐670GG, P = 0.451; Fas‐1377AG, P = 0.897; Fas‐1377AA, P = 0.881; FasL‐844TC, P = 0.119; FasL‐844CC, P = 0.454).